This study will quantitate in forearm muscle glucose phosphorylation, glucose transport, and intracellular free glucose concentration in controls, NIDDM subjects, and the normal glucose tolerant, insulin resistant offspring of two Mexican American parents with NIDDM. These measurements will be correlated with muscle HKII/HKI and GLUT4/GLUT1 mRNA and protein levels and HKII/HKI activity.